Description: This report on the Marbled Murrelet (Brachyramphus marmoratus) was compiled and editied by the interagency Marbled Murrelet Conservation Assessment Core Team. The 37 Chapters cover both original studies and literature reviews of many aspects of the species' biology, ecology, and conservation needs. It includes new information on the forest habitat used for nesting, marine distribution, and demographic analyses; and describes past and potential effects of humans on the species' habitats. Future research needs and possible management strategies for both marine and forest habitats are suggested.